How does it work?

Two illustrious individuals from each of the 18 countries are on the steering committee that organises the annual jamborees, serving four-year renewable terms.

The costs of a “small secretariat” are met “wholly by private subscription”, according to the group’s official website, while the bill for the conference itself is taken care of by the committee members from the host country.

Who gets to go to the sessions?

Chancellor George Osborne, a regular attendee, is on the roll of honour again this year. His former counterpart, Ed Balls, has also been asked despite humiliatingly losing his Commons seat at the election.

They will mix with other famous names including former MI6 chief Sir John Sawers, Dutch PM Mark Rutte, Google boss Eric Schmidt, and Nato secretary general Jens Stoltenberg.

Interalpen-Hotel in Austria where the Bilderberg summit is being held

What are they going to talk about?

A wide range of weighty topics are on the agenda: Greece, Iran, the Middle East, Nato, Russia, terrorism, the United Kingdom, the US and US elections.

But do not expect to hear what their conclusions are. The events are held under Chatham House Rules, meaning that while participants can use the information received, comments and views should not be publicly attributed to any individual.